Sliding door structure



Mafch 29, 1960 E. w. zEARFos, JR 2,930,667

SLIDING nooR STRUCTURE Filed Feb. 19, 1959 United States sLrmNG noon STRUCTURE Elmer W. Zearfoss, Jr., Philadelphia, Pa., assignor to Philco Corpuration, Philadelphia, Pa., a corporation of Pennsylvania Application February 19, 1959, Serial No. 794,321

Claims. (Cl. 312-304) The present invention relates to cabinet structure, and more particularly to sliding access doors for such structure. While'of broader applicability, the present invention has particular utility in refrigerator cabinets.

Sliding door apparatus advantageously tends to minimize environmental spatial requirements of cabinet structure so equipped, as compared with cabinetstructure equipped with hingedly mounted door apparatus.

However, so-called free standing, as well as modular, type cabinet structure is not well adapted for provision of recessed regions into which sliding door panels or panel means maybe moved when opening the same, and this problem has, heretofore, been met by provision of two or more otlset sliding door panels, each panel being arranged, selectively, for sliding movements with respect to the other panels and over the surfaces of the latter. Inasmuch as refrigerator door panels must be relatively thick to afford a suicient degree of thermal insulation, the outer surface presented by such relatively thick overlapping door panels is discontinuous to a degree rendering the cabinet structure unsightly. Also, useful cabinet storage volume is lost because interior regions of the cabinet adjacent a forwardly disposed door panel are unusable, inasmuch as such regions must be maintained free from obstructions in order that the rearrnost door may be moved, when opening the latter. Also, difficulties arise in the provision of an adequate seal between sliding door panels.

It is, therefore, a general objective of the present invention to provide sliding door apparatus overcoming the foregoing difliculties.

lt is a specific objective of the present invention to provide sliding door apparatus having improved thermal insulating characteristics.

It is another objective of the invention to provide sliding door apparatus of low thermal conductivity, and requiring a minimum of space. In the latter respect, it will be seen that, for a given insulating effect, the overall thickness of a pair of sliding door panels incorporating the principles of this invention is considerably less than the corresponding dimension in a pair made according to prior practice.

In the achievement of the foregoing, as well as other objectives, a preferred embodiment of the present invention contemplates provision of sliding door apparatus for a refrigerator cabinet having an access opening, said apparatus comprising a pair of slidably mounted insulating panel means mounted over said opening, each said panel means including a plurality of thin, closely spaced, confronting panel sections, the panel sections of each such means being fixed with respect to one another and disposed for interdigitating sliding movements between panel sections of the other means. g

It is a feature of the invention that overlapping of several panel sections of the complementary panel means provides a tortuous air leakage path eifective substantially to seal the door in the region of panel section overlap.

gaat? Patented Mar. 29, 1960 It is an additional feature of the invention that, due to the use of several thin panels, unusable storage area in the region of door overlap is minimized, as is the area of overlap.

lt is an important feature of the invention that spaces providing for interdigitation of the individual panel sections, when a door panel means is slid open, also serve as insulating, dead air spaces when the panel means are in their respective closed positions.

The manner in which the foregoing and other objectives may best be achieved will be clearly understood from a consideration of the following description taken in conjunction with the accompanying drawing, in which:

Figure 1 is a perspective showing of refrigerator cabinet structure embodying the invention;

Figure 2 is a somewhat enlarged sectional view, with parts broken away, looking in the direction of arrowsv 2 2 as applied to Figure 1;

Figure 3 is a sectional view, with parts broken away, looking in the direction of arrows 3 3 as applied to Figure 2; and

Figure 4 is a view similar to Figure v2, but showing a modification of the invention.

Now making more detailed reference to the drawing, and first to Figures 1 and 3 thereof, the illustrated refrigerator cabinet 10 is of the type havingrespective upper and lower sections 11 and 12. Section 12 is the base of the cabinet 10, and its top 13 is disposed forwardly of the lower portion of cabinet upper section 11. The aforesaid top 13 preferably is disposed at work-height, to serve as a worktable. A food compartment 14 is provided in the interior of section 12. The upper section 11 extends upwardly and substantially vertically from the rear of the work surface 13 and contains also a food storage compartment 15. These compartments, in both the upper and lower sections 11 and 12, have front access openings, with compartment 15 in the upper section 11 opening in a substantially vertical plane at the rear of the work surface 13.

Like closure apparatuses 16 are provided for both the upper and lower compartments, each apparatus 16 comprising a pair of complementary door panels or panel means 17 and 18 mounted on the cabinet for sliding movements toward and away from each other in the planes of the access openings of the said compartments. With this arrangement, opening and closing of the door panels 17 and 1S of the upper compartment does not necessitate removal of articles which may have been placed on the worktable surface, nor interrupt the use of said surface.

With further reference to Figures 2 and 3 of the drawing, sections 11 and 12 include a common outer shell 20, and inner liners 21 and 22 spaced one from the other as well as from the shell define, respectively, food storage compartments 14 and 15. A breaker strip 23 of low thermal conductivity extends between forwardly presented adjacent edge portions of the liner 22 and outer shell 20, and suitable thermal insulation 24 lls the spaces between the aforesaid liners and between the latter and the outer shell. Conventional shelf means, designated gen# erally by numeral 25, is provided for support of articles within the compartments.

inasmuch as structural features of lower section 12 are similar to like features of the upper section 11, no description of the former will be undertaken. Also, it is to be understood that cooling means for compartments 14 and 15 may comprise any one of known suitable designs, and need not be described in detail.

v Now making additional reference to Figures 2 and 3 of the drawing, door panels 17 and 18 areY mounted for sliding movements within respective upper and lower .5 channel means 2,6 and 27. The lower channel means 27 is conveniently molded into the lower horizontal portion of breaker strip 23 of the upper cabinet section 11. The upper channel means 26 conveniently is defined by suitably bent portions of the upper forward edge of the cabinet outer shell 20. A strip 31 of resilient material, for example rubber having smooth surface portions presented toward the door panels, is disposed between upper horizontal edges of door panels 17 and "18 and the web portion of channel means 26. Resilient strip 31 advantageously serves both as a seal between upper channel means 26 and upper edges of the door panels, and as means resiliently urging the door panels against the lower channel means 27. By virtue of this arrangement, panels 17 and 1S may be either removed or installed merely by moving the same to compress the strip 31 while moving lower edges of the door out of or into the channel means 27.

The lower edges of door panels 117 and 13 are sealed by a cantilever gasket 32 of suitable resilient material disposed along the'cabinet work surface 13 `and bearing resiliently against lower edge portions of the door panels adjacent thereto.

Vertically extending respective free edge portions 33 and 34 of door panels 17 and 18 are provided with resilient gasket strips 35, each disposedl to engage vertically extending surfaces of the cabinet presented toward the strips.

In particular accordance with the invention, the free edge portions 33 and 34 of the door panels comprise base means for a plurality of panel sections 36 and 37 disposed substantially in the planes of the respective door panels 17 and 18. The panel sections preferably are spaced equi-distant one from the other in a direction transverse the planes of each door panel, and the panel number of which materials are well known n the art.

In certain applications. the panels may desirably be transparent. In the embodiment shown in Figures 1, 2, and

3, each of the door panels 17 and 18 may, for example, y

be molded as a unit including thepanel sections and end portions, from a suitable plastic.

Thermal insulating properties of the door advantageously are derived, primarily, from the multiple dead air spaces 41 between panel sections of each door panel which provide for interdigitation of the panel sections ofv one multi-sheet panel between the panel sections of the other multi-sheet panel. It is further seen that clue to the labyrinth-like configuration provided by overlapping of the panel sections of the central region designated generally by the numeral 42, a substantially positive air seal between the door panels 17 and 18 is insured, and the overlapping seal area can be and is minimized.

From a consideration of Figure 4 it will be readily understood that the invention is susceptible ot a number of modifications, both as to panel section mounting and number. For example, door panels 17a and 18a each may comprise sheet-like members 43a and 44a, respectively, bent up into channel-like sections, the former having leg portions 45a disposed for overlapping sliding movements with respect to like leg portions 46a of 'member 44a; Panel sections 36a andV 37a are mounted to base means 33a and 34a, each of the latter being aixed to respective-web portions 47a and'48a of members 43m 44a. Accordingly, panel sections 36a are disposed for interdigitating movements, within guide track or channel 27a, between panel sections 37a. These sections may p assess? -f other panel in the region of overlap thereof as indicated generally by 42a.

Referring further to the apparatus of Figure 4, it will be seen that, if a still better seal is desired the labyrinthlike seal between the door panels may be augmented by a resilient cantilever gasket. Such a gasket is shown at 49 and is disposed upon the interdigitating leg portion 46a of member 44a and resiliently bearing against the adjacent leg portion 45a of member 43a.

While a minimum of spacing is desirable between panel sections in order to enhance the thermal insulating properties of the door, by lessening convectional ow of the air entrapped between thesections, structural rigidity of the interdigitating panel sections must be ensured. To this end, a door panel of the type shown in Figure 4, and exhibiting the aforesaid desired qualities, may comprise three 7/16-inch thick panel sections 36a and 37a of berboard spaced 1/z-inch apart and enclosed by suitable wrapper means 43m-44a. For example, the latter means may comprise bent-up sheets of 20 gauge aluminum, or, if desirable, similarly formed sheets of thermally nonconductive material, the panel sections and wrappers being so arranged as to provide three 1/-inch thermally insulative dead-air spaces.

It will of course be understood that the present invention contemplates provision of door panel means having panel sections of any suitable thickness and quantity affording the desired spatial and thermal insulating characteristics.

It will be understood that thermal insulating qualities of the vdoor structure further may be enhanced by providing heat reflecting layers of metal foil upon surfaces of the panel sections confronting the air spaces.

As respects the thickness of the door apparatus shown in Figure 2, as compared with prior art doors having single, lapped, non-interdigitating panel means, it can be demonstrated that for a given insulating effect, the overall thickness of the illustrated door apparatus is substantially less than the corresponding dimension of the prior art door apparatus. Stated another Way, for a given overall thickness, the interdigitating door apparatus of the present invention, as compared with a simple pair of overlapped sliding doors utilizing insulating material of a fKvalue equal to that provided bythe 1/t-inch dead air space described by way of example, will exhibit'improved thermal characteristics over said simple, lapped pair.

As respects the amount of offset between panel means, as seen in Figure 3, it is only asmuch as the thickness of a panel section 36 or 37. In the embodiment shown in Figure 4 the amount of offset is but the single-thickbe comprised of relatively thin sheets of berboard, or 'Y the like, and the'panel sections of one door panel pro,- videthe necessary spacing-bctweenpanelsections of the ness dimension of the relatively thin leg portions of wrappers 43a and 44a enclosing the respective panel sections 36a and 37a, these latter elements of each panel being cooperatively disposed with respect to one another to provide a plurality of insulating dead air spaces.

It will be understood that such modifications may be made in the illustrated embodiments asare contemplated by the scope of the appended claims.

I claim:

1. Sliding door apparatus comprising a pair of panel means, each slidablymovablerelative to the other and each including a` plurality of panel sections, adjacentl panel sectionsiof said means being spaced one from the other inz the idirectionofv the thicknessof the'door apparatus, and the sections. ot each. panelV means interdigitating betweenthe sections ofxthe. otherl panel means.

2. Sliding door apparatus comprising a pairA of panel means, each mounted for sliding movementsrelative to theother and each-including a plurality of panel sections disposedadjacent one another while being substantially equally spacedrone, from the other,A in. the direction of the vthickness of' the 'door apparatus, the panel sections of each panel means interdigitating between the sections of the other panel means.

3. In combination, cabinet structure having an access opening, and door apparatus mounted for opening and closing sliding movements over said access opening, comprising: a pair of panel means disposed substantially in the plane of said access opening, each said panel means being slidably movable relative to the other, each of said panel means having a plurality of panel sections, each said section being spaced one from the other in the direction of the thickness of said door apparatus, the sections of one said panel means being disposed and adapted for interdigitating movements between the panel sections of the other panel means.

4. A combination in accordance with claim 3, and being further characterized in that said cabinet structure is dened in part by thermally insulative walls and said panel means are cooperatively disposed, upon closing of the door apparatus, to form substantially dead air spaces between adjacent panel sections of a panel means.

5. A combination in accordance with claim 3, and

being further characterized in that said cabinet structure is defined in part by thermally insulative walls and said panel means comprise panel sections of thermally insulative material cooperatively disposed, upon closing of the door apparatus, to form substantially dead air spaces between adjacent panel sections.

6. A combination in accordance with claim 3, and being further characterized in that said cabinet structure is defined in part by thermally insulative walls, and that the thermal seal between one said panel means and the other is derived from the tortuous air leakage path extending through said door apparatus between adjacent panel sections.

7. In refrigerator cabinet structure, a cabinet having an access opening, and door apparatus slidably mounted over said access opening for opening and closing movements of the latter, comprising: a pair of insulative panel means disposed substantially in the plane of said opening, each panel means being mounted for slidable movements relative to the other, each said panel means having individual panel sections of low thermal conductivity, each said panel section being spaced substantially equally from the other in the direction of thickness of said door apparatus, the panel sections of one said means interdigitating between each panel section of the other said panel means, whereby dead air spaces are provided between adjacent panel sections of an individual panel means when said door apparatus is in its closed position.

8. Sliding door apparatus including a pair of panel means, each slidably movable relative to the other, comprising: a pair of channel-like members of sheet-like material, cach having leg sections and a web section, said web section of one member being spaced from the web section of the other member in a direction generally in the plane of the panel means and said leg portions of each of said members being presented toward and overlying the leg portions of the other of said members, said members being slidable toward and away from one another along said overlying leg portions; and a plurality of adjacent panel sections spaced one from the other and from said channel member leg portions in the direction of thickness of the door apparatus, the sections of each panel means interdigitating between the sections of the other panel means and being disposed for sliding movements relative to one another in response to relative sliding movements of said channel members.

9. A thermally insulative adjustable panel device comprising a pair of panel means, each including a plurality of panel sections spaced one from the other in the direction of thickness of the panel member, and the sections of each panel means interdigitating between the sections oi' the other panel means to maintain the spacing of the sections and provide a plurality of insulative dead air spaces between adjacent sections of each panel means.

l0. Sliding door apparatus comprising a pair of panel v means, each slidably movable relative to the other and each including a plurality of spaced panel sections, a pair of panel section support members each disposed at opposite edge portions of said door apparatus and providing the sole support for said panel sections, the panel sections of each panel means interdigitating between the sections of the other panel means in the region of adjacent non-supported portions of said sections to maintain the spacing of the latter.

References Cited in the tile of this patent UNITED STATES PATENTS 1,728,984 Starr Sept. 24, 1929 2,116,803 Spoerl May 10, 1938 2,120,783 Hoiman June 14, 1938 

